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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

28293 results found.

  1. GRB240713A: Swift/UVOT Upper LImits
  2. EP240708a: X-ray follow-up observations with Swift/XRT
  3. LIGO/Virgo/KAGRA S240716b: Updated Sky localization
  4. GRB 240713A: Swift-XRT observations
  5. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  6. GRB 240712A: Swift-XRT refined Analysis
  7. GRB 240713A: LAST optical upper limit
  8. LIGO/Virgo/KAGRA S240716b: Identification of a GW compact binary merger candidate
  9. Fermi GRB 240715A: Global MASTER-Net observations report
  10. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  11. GRB240715A: GRANDMA Optical Upper Limits
  12. GW s240422ed: Swift UVOT follow-up
  13. GRB 240712A: Swift/UVOT Upper Limits
  14. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  15. The EP-WXT source triggered on July 14th is likely a flaring star
  16. GRB 240713A: J-band upper limit from WINTER
  17. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  18. GRB 240713A: JinShan optical upper limits
  19. GRB 240713A: OHP/T120 optical upper limit
  20. GRB240713A: Optical upper limit with Kinder observations
  21. Fermi Sub-threshold Observation of GRB240713A
  22. GRB240713A : The first probable GRB Located on-Board SVOM by ECLAIRs
  23. EP240708a: GSP optical upper limit
  24. GRB 240712A: Swift detection of a burst
  25. LIGO/Virgo/KAGRA S240711cm: Coverage and upper limits from MAXI/GSC observations
  26. LIGO/Virgo/KAGRA S240627by: Updated Sky localization and EM Bright Classification
  27. Fermi GRB 240710A: Global MASTER-Net observations report
  28. EP240708a: NOT optical observations
  29. EP240708a: SVOM/C-GFT optical upper limit
  30. EP240708a: Optical upper limits with Kinder observations
  31. EP240708a: EP-WXT detection of a fast X-ray transient
  32. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  33. EP240703b: GSP optical upper limit
  34. EP240703b: TRT optical upper limits
  35. EP240703a: TRT further optical observation
  36. EP240702a: TRT optical upper limits
  37. IPN triangulation of GRB 240628B (short)
  38. LIGO/Virgo/KAGRA S240705at: Updated Sky localization
  39. LIGO/Virgo/KAGRA S240705at: Identification of a GW compact binary merger candidate
  40. EP240703a: BTA observations
  41. EP240703c: Kinder optical follow-up and Swift XRT observations
  42. EP240703a: Liverpool Telescope optical follow-up observations
  43. EP240703a: Kinder optical follow-up observations
  44. EP240703c: EP-WXT detection of an X-ray transient
  45. LIGO/Virgo/KAGRA S240703ad: Updated Sky localization
  46. LIGO/Virgo/KAGRA S240703ad: Identification of a GW compact binary merger candidate
  47. EP240703a/GRB 240703A: TRT and JinShan decaying optical afterglow candidate
  48. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  49. LIGO/Virgo/KAGRA S240422ed: Updated significance estimate
  50. The first three GRBs detected by SVOM: X-ray Upper Limits from EP-WXT
  51. EP240703b: EP-WXT detection of a fast X-ray transient
  52. EP240703a: EP-WXT detection of a fast X-ray transient
  53. EP240702a: GSP optical upper limit
  54. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  55. EP240702a: EP-WXT detection of a fast X-ray transient
  56. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  57. LIGO/Virgo/KAGRA S240630t: Updated Sky localization
  58. LIGO/Virgo/KAGRA S240629by: Updated Sky localization
  59. LIGO/Virgo/KAGRA S240630t: Identification of a GW compact binary merger candidate
  60. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  61. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  62. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  63. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  64. IPN triangulation of GRB 240619C
  65. IceCube-Cascade 240626A: Upper limits from a search for additional neutrino events in IceCube
  66. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  67. GRB 240627A: NuSTAR Detection of the long GRB
  68. GRB 240615A: SAI CMO J- band observations
  69. GRB 240627A: AstroSat CZTI detection
  70. EP240626a: Montarrenti Observatory optical upper limit
  71. LIGO/Virgo/KAGRA S240627by: Identification of a GW compact binary merger candidate
  72. GRB 240624A: Swift-BAT refined analysis
  73. EP240626a: EP-WXT detection of a fast X-ray transient
  74. EP240625a: NOT optical counterpart candidate
  75. EP240625a: EP-FXT detection of the X-ray emission
  76. EP240625a: EP-WXT detection of a fast X-ray transient
  77. GRB240624A: Fermi GBM Observation
  78. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  79. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  80. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  81. GRB240615A: Gemini-North observations of the BAT and XRT positions
  82. GRB240615A: Gemini-North observations of the BAT and XRT positions
  83. GRB 240619A: detection of a radio counterpart with AMI-LA
  84. GRB 240624A: Swift detection of a burst
  85. GRB 240619A: J-band detection with WINTER
  86. LIGO/Virgo/KAGRA S240622h: Updated Sky localization and Source Classification
  87. EP240618a: NOT optical counterpart candidate
  88. LIGO/Virgo/KAGRA S240621em: Updated Sky localization and Source Classification
  89. GRB 240529A: JinShan optical observations
  90. LIGO/Virgo/KAGRA S240621dy: Updated Sky localization and Source Classification
  91. LIGO/Virgo/KAGRA S240621eb: Updated Sky localization and Source Classification
  92. EP240618a: GSP optical upper limit
  93. LIGO/Virgo/KAGRA S240622h: Identification of a GW compact binary merger candidate
  94. LIGO/Virgo/KAGRA S240621em: Identification of a GW compact binary merger candidate
  95. LIGO/Virgo/KAGRA S240621eb: Identification of a GW compact binary merger candidate
  96. LIGO/Virgo/KAGRA S240621dy: Identification of a GW compact binary merger candidate
  97. GRB 240619C: NuSTAR automated detection of the GRB
  98. GRB 240619A: Fermi GBM Observation
  99. Fermi GBM Sub-Threshold Detection of GRB 240619C
  100. GRB 240615A: NOT optical observations

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